Donald Trump’s rhetoric about Mexico got a tongue-lashing Thursday, with U.S. Vice President Joe Biden calling it “dangerous” and a Mexican ex-president dropping the F-bomb against his border wall plan.

Speaking during a visit to Mexico City, Biden told President Enrique Pena Nieto that there has been “a lot of damaging and incredibly inaccurate rhetoric” in the US election, but that most Americans do not share those views.

“I feel almost obliged to apologize for some of what my political colleagues have said about Mexico, about the Mexican people,” he said.

While Biden did not identify any candidates by name, Trump has used the strongest words against Mexico’s government and immigrants during the race for the Republican presidential nomination.

Vicente Fox, Mexico’s president from 2000 to 2006, had harsher words, telling the US television network Fusion: “I am not going to pay for that fucking wall. He should pay for it. He’s got the money.”

The billionaire real estate mogul hit back on Twitter, writing: “Vicente Fox horribly used the F word when discussing the wall. He must apologize! If I did that there would be a uproar!”

Another former Mexican president, Felipe Calderon, also lashed out earlier this month, telling CNBC that the Mexican people “are not going to pay any single cent for such a stupid wall.”